Identification of trypanolytic Nbs. 2×10⁵ monomorphic T. brucei parasites were kept in HMI-9 buffer at 37°C and counted hourly.

<p>A) Percent of lysed parasites at different times after adding 1 µg Nb_An05 (▴), Nb_An06 (•), Nb_An46 (▾), Nb_An33 (○) (VSG∶Nb ratio is 1/20) and a control with no Nb (▪). B) Percent lysis of antigenically distinct trypanosomes (AnTat1.1, MiTat1.1, MiTat1.2, MiTat1.5 and MiTat1.6) after two hours incubation with 1 µg Nb_An05 (light grey bars), Nb_An06 (dashed grey bars), Nb_An46 (dark grey bars), Nb_An33 (white bars) (VSG∶Nb molar ratio of 1∶20) and a control with no Nb (black bars). C) Inhibition of Nb-mediated trypanolysis using three-fold molar excess of AnTat1.1 VSG after two hours incubation with 1 µg Nb_An05 (light grey bars), Nb_An06 (dashed grey bars), Nb_An46 (dark grey bars), Nb_An33 (white bars) (VSG/Nb molar ratio of 1/20) and a control with no Nb (black bars). D) Percent lysed parasites after incubation with Nb_An05 at 1 µg (▴), 0.5 µg (▾), 0.1 µg (□), 0.05 µg (•) and control with no Nb (▪). These data are typical results from three independent experiments performed in triplicate (±SD). E) <i>In vivo</i> effect of Nbs on parasitemia development and survival of C57Bl/6 mice infected with virulent monomorphic AnTat1.1A parasites, injected i.v. with Nb_An46 (▾), Nb_An33 or without Nb treatment (○). Antibody injections were given at daily interval, starting from day one until day four post-infection (arrows). (†: indicates all mice died).